“When I smiled at them, they scarcely believed it; the light of my face was precious to them” (Job 29:24).

You probably know that studies have found that smiling is good for you. Carefully controlled psychological experiments have proven that we are happy because we smile just as much as we smile because we are happy. Smiling – even forced smiling – has been found to relieve stress, and a 2010 study published in Psychological Science even showed that smile intensity in photographs predicted longevity.

But did you know that at least one study has found that the single most effective thing a person can usually do to enhance his or her relationships with other people is … to smile more often? So in the title to this post I do not mean to be flippant in paraphrasing the biblical injunction “Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven” (Matthew 5:16, KJV). Letting our “light” shine is clearly more than just smiling, it involves our “good works” – the whole range of our behavior and interactions with others – yet if smiling is such an important component of our relationships with others, shouldn’t we indeed smile more often?

We may not be able to find biblical verses saying “Jesus smiled,” but in his classic work The Humor of Christ, Elton Trueblood lists thirty passages showing the humor of Jesus in the Synoptic Gospels. There are many other examples in the Bible of things being said with evident humor that suggest smiles were often present on the faces of God’s servants (for example, 1 Kings 18:27); and verses like “Our mouths were filled with laughter, our tongues with songs of joy” (Psalm 126:2) had to involve smiling.

The point is, walking in God’s ways should produce smiles at least a portion of the time. This is particularly true because feelings of care and affection are frequently accompanied by smiles – if we are concerned and caring for others we will naturally smile even, sometimes, despite our own circumstances. In fact, just as experiments have found we can make ourselves happy by smiling, we can also make others happy by smiling at them. So there are at least two good reasons to be smiling, but it is something many Christians don’t do as often as we might expect. A surprising number of sincere believers live under a cloud of seriousness – at its worst it can be an expression of focusing on spiritual problems rather than the answers, though more often it’s just that we forget what an impact a smile can have.

So keep this in mind when you greet the world. As they say, if you see someone without a smile, give them one of yours. It’s not meant as pop-psychology advice to make you feel better, it’s meant as a small reminder that smiling is a part of letting our light shine. It certainly isn’t the most important part, but it may be the first thing that people notice about us and – as Job mentions in the scripture quoted above – it may be one of the things they firmly remember.